A variety of computer nodes may communicate with each other via a variety of communication links. Each node may function as a transmitting (source) and receiving (destination) device in order to exchange data and/or commands with each other using different communication protocols. Data and/or commands may be divided by the communication protocol into smaller packets of information for more efficient routing. A plurality of packets may be received and processed at the receiving node. As the amount of traffic increases, a congestion condition may occur at the receiving node.
When the congestion condition is encountered, some communication protocols specify that the receiving node send a pause type command back to the transmitting node. Upon receipt of the pause command, the transmitting node pauses or stops the transmission of any additional packets to the receiving node. The transmitting node may not send any additional packets to the receiving node until it receives another command from the receiving node indicating the congestion condition has ended. Alternatively, the transmitting node may wait a particular time interval before sending additional packets to the receiving node.
Such a stop and start method of handling congestion conditions suffers from several drawbacks. First, this method does not readily permit finer control over the bandwidth utilization of the communication link utilized by the transmitting and receiving node. This may create a larger latency variation for high priority traffic. Second, during persistent congestion conditions a plurality of pause type commands would be sent from the receiving node to the transmitting node resulting in poor bandwidth utilization of an already congested communication link. Third, the pause type command does not specify a quantity of available bandwidth for a given receiving node. Fourth, the pause type command may only be generated as a last resort resulting in an excessive amount of packets being dropped at the receiving node before the transmitting node stops sending additional packets. Fifth, longer latencies may develop if a lower amount of dropped packets are to be achieved as the transmitting node may spend more time in a pause mode not sending any packets.